Unit Test for Methods that Call Web API

HttpClient helps you interact with your Rest API’s through its asynchronous methods such as GetAsync. But on a TDD environment, it could become a challenge on how you could write Unit Test cases for a method that invokes the API via GetAsync and ensure that your call successfully invokes the API (considering your API sits in another server and calling it your unit tests would not be ideal). The way I approached this by creating a self hosted API within the Unit Test Project and make the Test Method calls to the API.

The first step was to use Open Web Interface for .Net (or OWIN) to self host an API. Microsoft has put on an extremely useful link for the purpose. Following become by code to configure the API.